As a precursor to this suggestion, this is my experience so far with microphones, and I think many other's as well. I find a microphone, try both female and male, both sound exactly the same on all characters. I'm not complaining, it makes sense that it's like this, as it gives more time for other things, however, I think that it's a little strange that Glitch, Floran, Hylotl, Avian, Apex, and Human, all sound the same. Here's my suggestion, though I don't know if this is plausible. Make the Do Re Mi Fa So La Ti Do for the different races and mod them as such- Hylotl - they live under the sea, which means they would talk at a much higher pitch and also clearer. Raise the pitch for both females and males, and make it less striking by removing a couple consonants from the sounds. Floran - Lots more emphasis on T's and S's, and a little bit of reverb, but not too much Glitch - I think this is obvious, (on a personal note, the singing Glitch would probably sound best out of all the races). Reverb, as well as some echo, as well as distortion. more emphasis on "z" sounds as well as "o" sounds. Avian - chirping, I can't find it anywhere, but there's a fan-made video with a talking avian playing beta, animated as well, my suggestion is for it to sound more akin to that sort of uncanny-valley-chirping (or maybe not) Human - already fine Apex - slightly more gutteral than human, these guys are physically de-evolved while mentally evolved, meaning they speak clearly, but their voice box is designed for grunting. These are the base thoughts of what I want to suggest, but again, I don't know if this is plausible or even necessary, just something I thought up to enhance the experience.
I agree, Glitch should have a better singing voice, since that's all that other races go on about. Would like it to be more robotic, too.
Hey! I hope you don't mind, I used the advice from this post on an audio file I made! It's a reading of 'A Plea to Self Aware Glitch', done by myself! You can find it here! Thanks again for making this post, it was a huge help!